1. Field of the Invention
The present invention relates to a multilayered ceramic capacitor and a board for mounting the same.
2. Description of the Related Art
A multilayer ceramic capacitor, a multilayer chip electronic component, is a chip-shaped condenser mounted on the printed circuit boards of various electronic products such as display devices, for example, liquid crystal displays (LCDs), plasma display panels (PDPs) and the like, as well as computers, smartphones, mobile phones, and the like, to serve to charge and discharge electricity therein.
Since such a multilayer ceramic capacitor (MLCC) has advantages such as a small size, high capacitance, ease of mounting, or the like, such a multilayer ceramic capacitor may be used as a component in various electronic devices.
The multilayer ceramic capacitor may have a structure in which a plurality of dielectric layers and internal electrodes having different polarities are alternately stacked while being interposed between the dielectric layers.
In particular, a power supply device for a central processing unit (CPU) of a computer or the like may generate voltage noise due to a rapid change in a load current during a process of providing a low voltage.
In addition, as efficiency of the power supply device has been important in recent years, a rapid switching speed is required for decreasing a loss of the efficiency.
However, when the switching speed increases, a negative offset phenomenon such as an increase in electromagnetic interference (EMI) may occur.
In addition, when field effect transistors (FET) configuring a direct current (DC)/DC converter are switched, ringing occurs through inductance in a wiring and parasitic capacitance of the FET to hinder a peripheral-circuit while emitting high frequency noise.
That is, resonance is generated by the inductance of the wiring and the capacitance of a switch device in the FET, or the like, and electromagnetic interference occurs due to the high frequency power.
In particular, since analogue circuits such as power supply circuits, wireless circuits, voice circuits, or the like, may be provided to be adjacent to each other in small, portable terminals such as smartphones, tablet PCs, or the like, EMI generated thereby may hinder communications or deteriorate sound quality.
In general, research into a technology of adding a C-R snubber to the FET in order to solve the above-described problems has been conducted. However, in the method of adding the C-R snubber to the FET, power is partially consumed in the C-R snubber at the time of switching, such that conversion efficiency of the DC/DC converter may be deteriorated.
Therefore, research into a technology of decreasing noise by suppressing the ringing while preventing the deterioration in the conversion efficiency of the DC/DC converter remains required.